Diaphragm for expansion valves



Feb. 2s, 1929. 1,703,531

R. M. HYDE DI'AIIHRAGM FOR EXPANSION VALVES Filed May 23, 1927 Aix Patented Feb. 26,1929.

lUNITED sTATEs PATENT OFFICE.

BOLLIN M. HYDE, 0F DETROIT, MICHIGAN, ASSIGNOB TO MCCOBD RADIATOR & MEG. C0., OF DETROIT, MICHIGAN, A CORPORATION OF MAINE.

DIAPHRAGM FOB EXPANSION VALVES."

Application tiled May 23, 1927. `Serial No.v193,455.

This invention relates to expansion valves for refrigerating machines, and more particularly to means for securing the light metal diaphragms in place in the valves and maintaining them under tension so that they will operate properly at all times.

Hcretofore, the practice has been to solder the outer edges of these light metal diaphragme in grooves machined in the bodies of the valves. The soldering operation, by reason of the heat employed, causes the diaphragms to warp because the heat can not be uniformly applied, and warped diaphragms have been a source of great annoyance in connection with these valves because they operate at a set pressure by means of the diaphragms. Moreover, in soldering the diaphragms to the valve bodies, considerable difficulty has been encountered in trying to keep the diaphragms perfectly flat when applied so that they will function properly in all valves at all times.

The main object of my invention is to clamp the diaphragms to the valve bodies without the use of solder, and thus avoid Warped diaphragms as the application of heat thereto in securing the diaphragrns to the valve bodies is entirely eliminated.

A further obj ect of my invention is to place the diaphragms under tension as. they are clamped in place and thus have perfectly flat diaphragms when applied, to act properly in all valves. v

One way to accomplish this object is to thicken the outer edge of the diaphragm as by a lead gasket and force this gasketed edge against an inclined surface which may be in a groove so as to exert an outward tension' on 'the diaphragm all around to stretch it and thus have it flat when applied to the valve.

The invention consists further in the 'matf ters hereinafter described and claimed.

In the accompanying drawings- Fig. 1 is a; top plan view of an expansion valve in which the diaphragm is secured in accordance with my invention;

Fig. 2 is an enlarged vertical sectional view A to the body 1 by screws 3, 3 about the outer edges of the cover and body, respectivel as shown. Disposed between the body 1 an the cover 2, in accordance with valves of this character, is alight metal diaphragm 4. In these valves, the opening and closing of the needle valve 5 is controlled by the flexing of the diaphragm 4. As the mechanism by which this is accomplished forms nofpart of my invention, it need not be described.l .All that need be said is that a coiled spring 6 in the cover 24 acts against the upper side of the diaphragm, while its under side is acted on by the pressure of the refrigerant passed through the body of the valve, as common in devices of this character.

In accordance with my invention, the outer peripheral edge of the diaphragm 4 is bent inward on itself to provide a channel 7 in which is rolled or otherwise fitted a relatively soft metal ringf8, which may be of lead, as shown in Figs. 3 and 4. The body 1 of the valve inside of the line of screws 3 is provided with an upwardly' facing annular boss 9, which supportsthe diaphragm -just inside of its gasketed edge 7-8. Machined or otherwise formed in the body 1 between the line of screws andthe boss 9 is an annular groove 10, which is provided with a downwardly inclined bottom Wall or surface 11, against which the gasketed edge of the diaphragm is forced by a rib 12 on the under side of the cover 2. With the bottom surface 11 of the groove inclined, as shown, the downward 'y the center of the diaphragm and thereby stretches the same over the boss 9 like the head of a drum to place the diaphra under tension and maintain it normally at, when applied, throughout all its portions over the body 1 inside ofthe boss 9. The greater the tension on the gasketed edge of the diaphragm the greater the stretching and the greater the sensitiveness of the diaphragm to pressure on its opposite sides.

In securing the diaphragm in place in the manner shown and described, all soldering as heretofore employed `for this purpose is done away with, which effects a tremendous saving 1n manufacturing as well as service costs. In addition, this method of securing the diaphragm in place keeps it normally flat when applied and in no way is it distorted or warped as heretofore. The result is that t-he diaphragms of all the valves produced will function properly.

The details of structure andY arrangement of parts may be variolisly changed and modified without departing from kthe spirit and scope of my invention.

I claim as my invention.:

l. An expansion Valve for refrigerating l machines having a body part and a" cover part, a flat relatively light metal diaphragm between said parts, and means for clamping the diaphragm in place, said means including 'edge of the dia hragm for increasing the thickness thereot, and means for clamping the diaphragm between the body and cover parts, said means .including on one part a support for the diaphragm and a surrounding groove with an inclined surface and a member integrallycarried on the other part suiiciently outward from the inner edge of said surface to engage the thickened outer edge of the diaphragm and force it into said groove and outward along said inclined surface for stretching the diaphragm over said support on clamping the body and cover parts together.

3. A11 expansion valve Jfor refrigerating machines having a body part and a cover part, a relatively light metal diaphragm between said parts, said diaphragm having its outer marginal Aedge bent to provide a channel, a relatively soft metal ring fitted in said channel to increase the thickness of the outer edge of the diaphragm, and means for clamping the diaphragm between the body and cover parts, said means including on one part a support for the diaphragm and a surrounding groove with an inclined surface and a rib on the other npart to engage the thickened edge ofthe diaphragm and force it into said groove and outward along said 'inclined' surface for stretching the diaphragm over the support 4on clamping the cover and body parts together.

4. A diaphragm for an expansion valve for refrigerating machines, said diaphragm being flat and made circular in form of relatively light gauge metal, saidv diaphragm.

having'its surrounding outer edge folded inward to provide an inwardly opening channel, and a ring of relatively soft metal fitting in said channel with the folded edge of the :diaphragm enclosing the outer edge of the ring and extending under the lower surface of the same for attaching the ring to the diaphragm.

In testimony whereof I atlix my signature.

ROLLIN M. HYDE. 

